JPH0358504A - Electronic scanning antenna - Google Patents

Abstract

PURPOSE:To attain the beam scanning even with a small angle and to decrease the blind sector by applying a bias when a command angle causing the initial blind sector is nearly 0 deg.. CONSTITUTION:A phase shift rounded off due to quantization is corrected by applying a bias with a large phase shift to a digital phase shifter 2 connecting to an antenna element 1 closer to the end than a digital phase shifter 2 connecting to an antenna element 1 closer to the center in digital phase shifters 2 receiving a phase shift calculated arithmetically at a phase shift calculation section 6 and being a half the total phase shifters at one side in a direction of scanning a beam in a line or in a face. Thus, the blind sector of a beam scanning angle with respect to a command angle signal 4 of the electronic scanning antenna attended with the quantization of the phase shift is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic scanning antenna that electronically scans the antenna beam of, for example, a radar, and in particular to improvement of its beam scanning characteristics.

[Conventional technology]

If you line up Figure 4, ``RADAR HANDBOOK (M
oGRAW1H LL, 1 9yO)l 1. −
r page. This is a configuration diagram showing an example of a conventional boson scanning antenna as shown in Fig. Digital polyphony device, 13)
(5) is a power supply unit that distributes the 1 power to each great phase shifter, and (5) is a beam steering computer (hereinafter referred to as BRC) that controls the digital phase shifter based on the command angle signal (4) K that instructs the direction of beam scanning. ), [61 is the command angle signal 14
), and (7) calculates the phase shift amount of the digital phase shifter using the phase shift information of the minimum bit of the digital phase shifter. (8) is a phase shift control unit that sets the quantized phase information to each digital phase shifter, and (9) is a central processing unit C.
PU, (II is memory, 1, above (6) to Il
1 is 13 SC! A conventional electronic scanning antenna, which may be a product with a structure of
4), each digital phase shifter 12) is
[Problem to be Solved by the Invention] In the conventional ray-scanning antenna as described above, the phase shift of the minimum bit of the digital phase shifter (2) 1, and each digital phase shifter (2
), the direction of the antenna beam does not change even if the value of the command angle changes over the range of △θ, when the command angle is around the angle θ0 shown by the following equation.
There was a problem that a so-called dead zone occurs. Here, Φ0 is the phase shift of the minimum bit of the digital phase shifter (2) (degree), λ is the wavelength of the radio wave (beat), and α is the spacing of the antenna element (1). (mm). N is the antenna element (11) This invention was made to solve this problem. [Means for solving the problem] The electronic scanning antenna according to the present invention aims to reduce the impedance band.
In addition to the phase shift information calculated in step 61, a digital phase shift 2 of only one side i1111 in the direction of scanning the beam in rows or planes is applied.
; For +21, the digital phase shifter +21 connected to the antenna element (1) closer to the seat than the dizotal phase shifter (2) connected to the antenna element (1) near the center.
A bias with a phase shift amount larger than K is heard before being quantized, and a beam command angle for directing the beam in a certain direction in the beam tilt correction unit II3 and a beam directing angle indicating the direction in which the beam is actually directed are determined. Before calculating the amount of phase shift, an isometric calculation is performed to multiply the beam command angle by the specified Tsunemaki K so that the ratio of fVC approaches fVC. Based on the corrected angular error signal, the drive of the antenna element (1) is controlled, and in the antenna element control unit (fl4), the antenna element fil is controlled according to the command from the antenna element drive control unit (l1). The amplitude t of each antenna element [+1] is changed to control the actual driving of the antenna element (1), and in terms of the antenna element rotation axis, the antenna element (
1) In this invention, if we explain the case where the command angle at which the first fuwa belt occurs is around 0°, for example I+'l1, the range of the fuwa belt is When attempting to scan the antenna beam using an angle smaller than △θ as the command angle. If there is no bias, it will be cut off due to emotionalization, so it will be ignored.

On the other hand, by adding a bias, the beam is rounded up by Keiko, so that it is no longer truncated, and the beam can be scanned even at an angle smaller than △θ, and the dead zone can be made smaller. This is a diagram showing an example of a real tree (1) ~
01 is exactly the same as the conventional device mentioned above.

[II1 Biased IJ1'1 which adds a bias to the phase shift information before it is changed to a bias The ratio of the beam command angle, which is the first part, and the beam directivity angle, which indicates the direction in which the beam is actually directed, approaches 1. This is the beam inclination correction section that performs the ``K'' calculation, which multiplies the specified constant K to the beam command angle.
tll is the angular error signal for the non-regional portion generated in the beam tilt correction section (the angular error signal is the ratio of the beam directivity angle to the beam command angle) In order to bring it close to 1, the beam tilt correction section corrects it by a prescribed constant K, and the drive i cob of the antenna element (1) is controlled based on the analog error generated in the beam tilt correction section. It is the antenna element drive control unit! I4 is an antenna element driving section that actually drives the antenna element l1). 6 is the antenna element pharyngeal rotation axis that rotates the antenna element +11, phase shift view? + Atsube (6) Is the amount of phase shift calculated by the arithmetic calculation only half of the direction in which the beam is scanned in a row or plane? Regarding the digital phase shifter (2), the 4K
By applying a bias with a large amount of phase shift to the digital phase shifter (2) connected to the nearby antenna element (1), it is possible to correct the moderate phase that is cut off by the phase change. are calculated changes in the beam scanning angle with respect to the command angle signal 14}, and show the encounter of the point decoy with the conventional beam, and the actual point with the current of the device according to the present invention. 1 draw command meat shop number 14), S indicates the beam travel angle, the number of antenna elements in one plane is 10 elements, the element spacing is 15, the S length is 30 s Digital phase shift 6 12+
Number of bits - ¥ - 4 bits (Binoto's phase shift is 22
．． 5°).

FIG. 3 shows the bias amount of the 13th case of this invention in the calculation example shown in 21.2. The beam directivity characteristics shown in Fig. 2 were simulated by changing the bias in the phase amount calculator (7) that determines the amount of phase shift sent by each digital phase shift (2) VC. It was found that the quadratic yellow bias number 1 shown in Figure 3 had the highest beam directivity characteristics in the Ki prefecture.

In the figure, . The 'ii axis shows the antenna element number, and the vertical axis shows the bias number. It is possible to reduce the dead zone of Pino and scanning angle for the angle signal +41,

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is an example of an effect drain of the invention, and Fig. 3 is an example of a bias plate for a phase shifter according to the invention. FIG. 4 is a block diagram showing an embodiment of a conventional device. In the figure, f1} is an element antenna, ! 2) I-f digital phase shifter, f3) is the power supply section, 14) is the command angle signal, (5) is the BSO, +61 is the phase shift amount measuring section, (7) the phase shift t calculation section, (8) ) is the phase shifter control group, (9) is the CPU,
01 PaMemo 1 C [111 is the bias addition section, L6 is the beam tilt correction section, (I3 is the antenna element drive control m, +
14 is an antenna element drive unit, n! 9 indicates the axis of rotation of the antenna element 11. In addition, the same reference numerals in each figure indicate the corresponding parts. Kochihi; Ichita (EISC) 5:
Antenna Hayabusa Senkoran” Yu No. 9 Diagram I Schiff 3 Diagram

Claims (1)

[Claims] A plurality of antenna elements arranged in a row or a plane, digital phase shifters connected to each of the antenna elements, a power feeding section that distributes power to each of the digital phase shifters, and a beam scanning device. A phase shift amount calculation section that arithmetic calculates each phase shift amount of the digital phase shifter from the command angle signal for a phase shift amount calculation unit that sets the phase shift amount quantized by the phase shift amount calculation unit to each digital phase shifter, and a beam steering computer having a CPU and a memory. , in an electronic scanning antenna that electronically scans the antenna beam, the phase shifter calculated by the phase shift calculation unit is added to the center of the digital phase shifter for only one half of the direction in which the beam is scanned in a row or plane. A bias adding section that applies a bias with a larger phase shift amount to a digital phase shifter connected to an antenna element closer to the end than the digital phase shifter connected to a nearby antenna element before quantization; In order to bring the ratio between the beam command angle and the beam directivity angle, which indicates the direction in which the beam is actually directed, closer to 1, an arithmetic calculation is performed by multiplying the beam command angle by a prescribed constant K, and the output thereof is given to the phase shift calculation section. a beam tilt correction section; an antenna element drive control section that controls the drive of the antenna element based on the uncorrected angular error signal generated by the beam tilt correction section; An electronic scanning antenna comprising: an antenna element driving section that drives an antenna element; and an antenna element rotation axis that is provided between the antenna element and a digital phase shifter and that drives the antenna element.